Supply roll tension in a measuring instrument



P 1952 G. w. BARNES, JR 2,612,323

SUPPLY ROLL TENSION IN A MEASURING INSTRUMENT Original Filed Apl il 12, 1944 5 Sheets-Sheet l DIRECTION OF F CHART MOVEMENT I32 m lzq 5 I26 |2a W1 m Wad I25 II 1 I33 I w i23 4 F 7 I22 III e "5% I21 6* l9 M a I JNVENTOR.

I a "a GEORGE w- BA NE I H6 1 I g, 34 71 E" i '09 t 3 7 ATTORNEY.

Sept. 30, 1952 G. w. BARNES, JR 2,512,323

SUPPLY ROLL TENSION IN A MEASURING INSTRUMENT Original med April 12, 1944 3 Sheets-Sheet 2 FIG. 2

75 JNVENTOR.

GEORGE w. BARN Es, JR.

ATTORNEY.

Sept. 30,- 1952 e. w. BARNES, JR

SUPPLY ROLL TENSION IN A MEASURING INSTRUMENT 5 Sheets-Sheet 3 Original Filed April 12, 1944 R J R. S) m E N N E R V A m 8 mm w E wk G mm R O E G v n N2 I n H w 0 I now L m3 I EN #8 9m mom EN 5 n F ATTORNEY.

Patented Sept. 30, 1952 v UNITED STATES PATEN SUPPLY ROLLTENSION IN A T INSTRUMENT M AS R G George 'w. Barnes, Jr., Clifton Heigh-ts,'Pa., as-

signor, to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn, a corporation of Delaware Original application April 12,- 1944, Serial No.

530,611, now Patent No. 2,527,207, dated-Octm her 24, 1950. Divided and this. application January '27, 1949,'Serial No. 73,162, l

In mostrecordin-g instruments the value of a single condition is recorded against time bymoving a marking element in one direction and moV- ing the chart upon which the record is made at right angles thereto and' at a constahfspeed. There are times, however, where it is more desirable torecord-the value of one condition with respect to-the value of a second. In such a case a more'complicated instrument-is necessary since means must be provided for moving the marking element in twodirections.

The instrument of the present invention is pro vided with a pair of motors each one of which,

through suitable mechanism, serves to move the recording element across the chart in one direction. Each of these motors is controlled in its rotation by means of an amplifier that is responsive tothe-variationsin a minute'electric voltage.

This voltage is di re'ctly responsive to variations in the conditionbei rig measured, such for example, as the voltage produced by a'thermocouple if temperatureis -bei ngmeasured, or from a tachometer generator i-f speed is'beingmeasured. The chart upon" which the record is made is drawn with rectilinear coordinates and is'manu ally moved to bring a new surface under the remu'st lie-provided to hold'it flat and taut. Means must. also 'be provided to advance the chart to bring anew portion thereof into recordingposition. The 'usedchart may either-be Wound into a roll to be examined later or may be torn oli in sections. It is, accordingly, a specifioobject of the.- invention to provide an improved means to advance-a chart to bring unused portions there,- of into recording position. It is a'further specific object of the invention to provide a means'to maintain the: chart flat and-taut while airecord v} isbeing' made upon it.

' It will. be obvious to those skilled in the art I that: twovariables may be plotted against each other such as temperature against pres-Q. sure, speed against distance; 'sp ejcific' gravity against flow, or other variables? (01. z -75y c.

The various features of novelty which characterizethis invention are, pointed out with particularity-in the claims annexed to and forming apart'of this specification. For a better under- 5 standing of the invention, however, its advantages and specific objects obtained with its. use, reference should be had to the accompanying drawingsiand descriptive matter in which is il-j' of the invention.

In the drawings:

lustrated'and describeda preferred embodiment Figure 1 shows a front view of the instrument" with the casing door open, Figure 2 is a back View ported on the chassis; I

' Figure 3 is a top View of the chassis, f

Figure 4 is a bottom view of the chassis,

Figure 5 is a View of the taken on line 55 of Figure 3, I v v p Figure 6 is a view taken on line 6+6 of Figure i" ,v

Figure 7 is a sectional. viewof theichartsupporting roll.

Referring' first' to Figure 1; there is shown an "instrument casing I which is rectangular in shape and which. has a door .2. mounted thereon by hinges 3. I The door is shown in its. open position so thatthe parts within the casing. may be seen; The chart supporting mechanism and 0*the recording mechanism are both mounted on. a chassis '4 that is swingably mounted ,in the, instrument casing. 'lZo this end the chassis is, provided with hinge' members 5 thatncooperat'e' ,o with hinge members Son the casing. 1 Hinge pins vv extendthrough the members "5 and 6, so that cording element each time a record is to be'mader 'Since the chart is held stationary while the. record or records are made on it some means strument thatiareilocated on the back ofthe.

chassis, as shown in'Figure2, .or to-parts that. may be attached to the inside of the casing Without are located on the chassisand in the casing two self-balancing electrical networks one of which is capable of driving a pen in a vertical direction and the other of which is capable of driving the pen in ahoriz'ontal direction across a-chart in response tovari'ations in twovariable conditions.

no part of the invention claimed herein, ,It can be said however, that there is provided a motor OFFER of the mechanism sup paper feeding rolls going into detail, it is sufiicient to say that there,

The details of the construction by means of which this may be accomplished are fully setforth in the above identified parent application, andform 3 21 which when energized serves to move the pen horizontally. There is also provided a motor 48 which when energized serves to move the pen vertically} i f As the electrical networks rebalance themselves and cause motors 21 and 48 to rotate,- the V pen will be moved across a chart 'that is shown as being in strip chart form and'upon which are printed a plurality of individual charts made up of rectilinear coordinates. The chart supply roll 65, as best shown in Figure 3, is mounted on'one side of the chassis 4 while the ,take-upjroll B6 is shown on the other side of the chassis; On its The supply roll 65 is mounted upon a core which is so designed that a slight tendency to rewind the chart upon this roll is at all, times present, which tendency .can be overcome by the slipping of a friction clutch when the chart is moved-- Thusthe chart is at all times held under tension so that the portion thereof in front of the platen will always be taut. As shownin Figure 7, the supply roll support consistsfof a shaft 12 upon the upper end of which is rotatably mounted an elongated collar '53 and upon the lower portion of which is mounted a second collar 14. These collars serve to support a drum 15 that has rigidly fastened to its lower end a flange 16. The chartsupply rollisrriounted on the drum l and is kept from rotating with respect thereto by: means of a spring 11 whose upper end is adapted to be received in the usual notch formed in the core of the chart roll. This spring is attached to the collar 13 by means of a screw 19 and its upper end extends through a notch 19 formed in the surface of drum 15. The upper end of the shaft 12 has non-rotatably mounted on it a collar 8| that is provided with .anfenlarged upper portion on the top surface of which is fastened a member 82 having flat sides. Slidably mounted on the collar 8| is a disc 83 which is pressed'upwardly into engagement with the lower surface of the enlarged upper portion of the collarby means of a' sprin 84. Shaft 12 also has rotatable upon it one member 85 of a jaw clutch that is attached by a pin 96 to the collar 14. The member 85 has a jaw 81 projecting downwardly'from it which is adapted to engage a jaw 89 projecting upwardly from a second clutch member. 88 that is also freely rotatable upon the shaft I2. These clutch members are normally maintained in the relation shown, in which the jaws 8'! and 89 do not engage each other, by means of a torsionSpring-Bl that hasv one end projecting into the clutch member 85 and the other 'end'projecting into the clutch member 98. Engaging the lower surface of the member 98 is a disc 92 of friction material that is pressed upwardly into engagement with the member89 by means of a disc 93 that is slidably received on the lower end of the shaft 12. The shaft at, this point is provided with flats on its surface with which the disc 93 cooperates so that it will not rotate relative thereto. Clutch member. 88, disc 92, and disc 93 are forced into en- After the supply roll 65 has been placed on drum 15 with sprin 11 in a notch in the roll core, the assembly is placed in position in the chassis (Figs. 2 and 3) with part 82 received in a slot 91 formed in a bracket 96 attached to the top of the chassis. The lower end of shaft 12 is received by an opening in a bracket 98 attached to the lower end of the chassis. The chart roll is maintained in the proper vertical position by a screw 99 that is threaded into the bottom of bracket 98 to limit the downward movement of shaft 12. Washer 93 bearing against the lower surface of bracket 96 under the force of spring 84 assists gravity in holding the assembly in position.

In operation, as the chart is moved across the surfaceof the platen the chart roll will cause the drum 15 to rotate with it. As the drum rotates it will first move clutch member until the jaw 81 thereof engages the jaw89 of clutch member 88. Thereafter, the clutch member 88 will also be moved against the friction provided by the engagement between its lower face and the friction disc 92. When the chart has stopped being moved spring 9| will tend to unwind it-' self to separate jaws 81 and 89 and thereby place the chart under tension. From the above it willbe seen that when the chart is initially moved, the spring 9| is placed under tension and thereafter the chart drum"|5 will be rotated against the friction of the disc 92. When the chartis no longer moved, clutch member 88 will remain in its new position and the spring 9| will place the chart under tension.

The take-up roll 66 (Fig. 1) is .placed on a drum |9| and is held in position thereon by a flange I02 on the lower end of the drum against to the chassis with the lower end of shaft I03 in a suitable bearing in the frame. Collar lfls'is held in the frame I05 bymeans of a collar H86 that bears against the bottom of the frame under the force of a spring I01. If desired the take-up roll can be rotated manually by means of a knob H18, but the take-up roll is ordinarily driven by frictional engagement between its surface and the surface of a friction driving roller I09.

The friction drive roll I99, (Figs. 3 to 6) is rotatably supported in an upper arm I and'a. lower arm H2, Which arms are pivotally mount-,

ed on a vertically extending shaft 3. In order that the arms may have a good bearing on shaft 3, each of them has a sleeve attached to it through which the shaft-extends. sleeves is shown at H4 in Figure 5 as being at tached to arm I. It is noted that guide roller 69 is also mounted to rotate around shaft I I3 and end a spring I l 5 is wrapped around the sleeve 4 and has one end attached thereto, while the other end bears on a portion of the chassis 4. This spring serves to force the arm I I2 in a clockwise direction in Figure 4. Arm I'll (not shown Figure 4) moves with arm l2. I r

A special construction is used on the upper an One of these 5 lower ends. of roll I09 to make. sure. that; there will. be sumci'ent friction. between: that roll and.

thetake-up roll 661todrive the latter. Since the; upper: and lower. endsiof the: frictionCdriving roll are: made: in exactly the. same: manner, only. the

upper end thereof is .shownin .sectionin Figure 5;

zeta-32s;

tion-driving roller: -l'09;. around; in frontof: that? driving; rolli and behind: a "cutter member: I 34;

' Wlien1thistype offchart: drive. is used; the: chart forwardly below the. cutting edge.

is pinched between. rolls I'Iv and I09- to; be fed chart hasbe'en advanced.- sufficiently; itmay. be

It will. be-seen that this; drivingfroll: ismountedr upon. sleeves I I6 that: are in. turn. attachedtd a" shaft II1 by mean-ssof aset screw' I119; The shaft.

I I1: is suitably journaled: for rotation. in arms ILIII and H2; The upper'endof the sleeve II6=is:re-

du'cedin diameter. as shown, andhasi placed upon 1 it a numberof friction. discs I.I.9 that-maybe made of. some: material such: as:composition cork" or fibre. These discs are tightlyhel'd'in 'enga'ge Rotation is imparted to thedriving roll I09'by' means. ofia gear I22 fastened tothe upper end of the shaft I I1. This gear meshes with apinion I23 mountedon thearm H I-, which pinion inturn is: driven by agear I24. As shown in Fig-ure inactive positioniuntil itis released by removing pulled do-wnwardly againstlthe-cutting :edge to be torn off? in sections; Anv indicators'l30" on the.

chassistE'is-L 1 cooperates with-the chart to show when: it is properly positioned.

In ord'er' simplify the? attaching ofrthe chart to takeeup roll and the threading off. the chartaround 'guide rollers '69 and", a means is provided to: hold the frictiondrive roll I09 out of i engagement-with the takevup roll 66. For this purpose a hook I40 (Figs. 1 and 4) is fastenedto the lower portion: of the: chassis. When. a new chart is-to' be placed in'th'e instrument thefricr tion drive roll I09 is moved clockwise in Figure 41 against the force of spring I I5untilthe hook I40 isengaged behind the bent-edge ofthe-cutter bar I34; The friction drivero-llwill then-be held in the. hook fromthe cutte'r bar.

Thepen' IE3 5' which'is-used to make a record 'on the charttismount'ed onaverticallykmovablecar'- 1 riagei 1451 that is in turn :mounted ona-horizonthis gear has'a tubular extension that is journaledin the chassis 4 and which is attached to a bevel pinion I25. The upper end of shaft H3 is re- 1 ceived by the bevel pinion which acts as a bearing therefor. The pinion I25 meshes with a second beveled pinion I26 that is attached to a shaft In which is journaled in bearings I28. In the operation of the device, a knob I29 on the front end of shaft I21 is rotated to rotate the pinion I26, and the various gears forming the gear train between that pinion and gear I22, so that the drum I09 can be rotated to drive the take-up roll.

' Normally the knobv I29 is rotated in a direction spring I33 that loosely encircles the bushing and which has one end attached to thecup shaped member. This spring is wound in such a direction that upon rotation of the shaft I21 in a diwill tend to expand into engagement with the inner surface of the cup member. Uponrotation of the shaft I21 ina reverse direction, however, the spring I33 will grab the outer surface of the bushing I3I to prevent or retard rotation of the I rection to feed the chart to roller 66, the spring shaft I21 in that direction. From the above it I will be seen that since the friction roller I09 cannot turn in a reverse direction, the spring 9| inv the supply roll can pull the chart tight without having a tendency to unwind it from the take-up roll.

v -At times it may be desirable to tear off each of the sections of the chartafter it has had a record drawn upon it, rather than saving all of these sections in a roll. If this is the case, the chart will be directed from the guide roll H, as seen in Figure 3, between the drum IOI upon which the take-up roll 66 is normally mounted and the frictally movable frame 221'. of mounting, the: pentcansbe movedfin any direction' across-the: chart td record the varying values of the two conditions that 'areb'eing measuredi The frame 22I carrying the pen carriage and pen is moved horizontally across the front of instrument by means of the motor 21 in response to unbalance of one of the above mentioned electrical networks. Tothis end, the motor 21 is attached to the lower part of the chassis 4 on the back thereof, as shown in Figures 2 and 4. As the motor rotates, it drives a pulley I11 through suitable gearing, including a gear I18 that is formed on the pulley. Rotation of the pulley is transferred to the frame by means of a cable I19 which has its ends wrapped around and attached to the pulley I11. The central part of the cable extends from the lower surface of the pulley around guide pulleys I BI and I82, the latter of which is biased in a clockwise direction in Figure 4 by a spring I (Fig. 2) in order to keep the cable under tension. Movement of the cable as the pulley. l11 rotates is imparted to the frame due to the fact that the cable is attached to a casting I6I ,of the frame 22I by means of a block I83 which grips the cable between itself and the casting. A screw I84 is provided for this purpose. The pen carriage is moved vertically on frame MI by the motor 48 in response. to unbalance of the other electrical network. For this purpose.

the motor is mounted on the lower portion of the chassis 4 and over to one side beyond the travel of the frame. The motor drives a splined shaft 205 extending transversely across the lower portion of the chassis of the instrument and journaled for rotation therein. As the splined shaft 205 rotates, it rotates a pulley 208, as shown in Figure 4 which pulley is slidably received on the shaft 205 and is moved along the shaft as the frame moves by portions of the casting I6I which engage its sides. The pen carriage is raised and lowered by a cable 209 which has its ends fastened to pulley 208. The center portion of the cable passes over a pulley 2I0 as shown in Figures 1 and 3, which pulley is mounted in the upper portion of the movable frame 22 I.

From the above it will be seen that there is provided a mechanism to move a pen in two direc- When the Because of this type tions" across a. chart. Thereiis', also providedza mechanism to. support a supply'roll of 'chart; and move the chartacross a platenand hold it taut in recording position. The chart-may be" either rerolled or' torn off in sections,'was desired. a

While in accordance with "the? provisions ,ofithe statutes, I have illustrated and described'the'besty; form of this invention now known to me; it would ,7 be apparent to those" skilled in the. "art; that changes may be made in theform of the apDa-fi ratus disclosed without'departing from the-spirit of this invention as set forth in the appendedclaims, and that in some cases certain features of this invention may sometimes be; used to acl=,

vantage without a corresponding-.useoflother features. I r

Having now described this invention-what, It

claim as new and, desireto-secure by Letters Pat.- entis: I I i I i 1. In a recording. instrument having a (chart upon which a record is. to"be drawn, means to hold a supply roll of the chart comprising a shaft fixed against rotation, a drum upon which asupply roll of chart is to be placed, meansto'rotatm, ably mount said drum onisa'id shaft,'a firstpart fixedto said drum, a second part on said; shaft,

means resiliently tending to hold said parts in a? positionthat is disturbedwhen a portion of char t.

is unwound from achart supply roll, and means to frictionally maintainsaid' secondpart against rotation onsaid shaft. 1 V i -2. In a recording instrument having awchart upon which a record is tabeniade, means tosupr port a supply roll-of chartcomprising a'shaft fixed against rotation in theinstrument, a drum rotatably mounted on said shaft, a first part having'a projection thereon attached to said drum, aisecond part having a projection thereon carried by said shaft, said projections cooperating to'permit limited movement therebetween, means resiliently holding said parts at one limit of their movement, saidparts .being moved to the oppo"-- site'limit of their movement :when said drum is rotated as the chart is unrolled, and means to frictionally maintain said second'part against ro- Name v Date ;630,601 Egry et a1., Aug. 8,1899 877,232 Rolland Jan. 21, 1908 1,831,790 Leong, Nov; 10, 1931 r 1,969,877 Doty Augtli, 1934 2,139,784 Wengel Dec. 13. 193 1 

